Generally, a substrate processing apparatus which is used for performing semiconductor unit processes for manufacturing of semiconductor devices may include a substrate plate within a chamber, on which a substrate is seated. A plurality of lift pins for lifting the substrate may be installed in the substrate plate to be spaced apart from each other. However, when an upper part and a lower part of the substrate plate become misaligned as a result of parallelism discrepancy due to machining and assembly tolerances for the lift pin hole of the substrate plate, lift pin driving plate, etc., and distortion due to vacuum formation, etc., particles may be generated by tilting of the lift pin, and interference between the lift pin and the substrate plate may lead to the lift pin being broken by stress concentration.